Re: Remove diff machinery dependency from read-cache

[Nicolas Pitre <nico@fluxnic.net>]

On Thu, 21 Jan 2010, Junio C Hamano wrote:

> Linus Torvalds <torvalds@linux-foundation.org> writes:
> 
> > On Thu, 21 Jan 2010, Linus Torvalds wrote:
> >> 
> >> We could fix it a few ways
> >> 
> >>  - ignore it. Most git programs will get the pack handling functions 
> >>    anyway, since they want to get object reading.
> >
> > In fact, we should probably remove git-show-index. It may have some 
> > historical significance as a pack-file index debugger, but it has no 
> > actual redeeming features now, considering that the binary is a megabyte 
> > of useless crud with debugging info.
> >
> > However, we do actually use it in t/t5302-pack-index.sh. So in the 
> > meantime, how about this hacky patch to simply just avoid xmalloc, and 
> > separating out the trivial hex functions into "hex.o".
> >
> > This results in
> >
> >   [torvalds@nehalem git]$ size git-show-index 
> >        text    data     bss     dec     hex filename
> >      222818    2276  112688  337782   52776 git-show-index (before)
> >        5696     624    1264    7584    1da0 git-show-index (after)
> >
> > which is a whole lot better, no?
> >
> > (Or make it a built-in, if we actually think we want to carry it along in 
> > the long run)
> 
> We tend to not remove things unless we are absolutely certain nobody uses
> it, so probably making it built-in would be preferrable.  I don't think
> show-index is used very often if ever, but scripts that use hash-object
> would use it really often and would do so via its --stdin interface if it
> knows that it is creating more than a dozen objects, so start-up time
> required to map the whole git is probably not an issue.

I do use it, but for developing/debugging pack stuff.
I don't suggest removing it, but I don't think making it a built-in has 
value either.

So I really think that Linus' patch (which is missing hex.c btw) is a 
good thing to do, even if only for the cleanup value.

Then, git-show-index could probably become test-show-index and no longer 
leave the build directory.


Nicolas